Growing global concern over persistent plastic waste has generated much interest in biodegradable polymers for everyday use. Biodegradable polymers based on polyhydroxyalkanoates (PHAs) and poly(lactic acid) (PLA) are an attractive alternative as they can be readily produced from renewable agriculture resources. Recent developments in manufacturing polymers from agricultural sources have accelerated the emergence of these polymers in the biodegradable plastic commodity market.
The commercial potential for PHAs and PLA spans many industries, and is derived primarily from advantageous properties which distinguish PHA and PLA polymers from non-biodegradable polymers. Widespread use of PHAs and PLA, however, has been hindered by difficulties in developing acceptable means by which these biodegradable polymers can be efficiently and economically processed into commercially attractive products. One important application of biodegradable polymers is in the area of disposable, one-time use items, such as containers and food packaging. There is a need for foamed thermoplastic materials that have a low density, lightness in weight, and enhanced biodegradability compared to foamed polymers derived from non-renewable resources.